To be blunt: No. In the United States there is no official criteria or system to define what type of seafood is sushi grade. Like many terms used in the seafood industry, sushi grade, sashimi grade, and similar sounding titles have more to do with marketing. Fishmongers long ago realized the public will accept previously neglected fish if they simply give it a new name. The most famous example being Chilean sea bass, which sounds way more tasty than Patagonian toothfish. When it comes to fish being marketed as sushi grade it is the same thing: fresh yellowfin tuna sounds good, but sashimi grade ahi sounds better.
When a company markets a product as sushi grade fish, what they are really saying is “this is the best that we have.” However, that is not the same as “this is the best you can get.” But a consumer can be forgiven for thinking that, since there is no quality standard for sushi grade fish and shellfish. The standards for sushi fish, come strictly from a human health standpoint.
What fish can be used in sushi does not factor in quality or taste, it only matters if it can get you sick. I’ve picked enough worms out of fish fillets in “candling rooms” to know about fish parasites. Some of these are harmless to humans but many others, like those that infest salmon can mess you up. Although not all sushi contains raw fish, any fish that will be eaten raw must first be frozen and stored for at least a week at -4F. This FDA guideline is to ensure that these fish parasites and their eggs are killed off.
Of course, these safety standards go right out the window, regardless of fish quality, if it is cross-contaminated with fish not prepared for sushi. Using the same cutting boards and knives, not changing food-prep gloves, even storing sushi and non-sushi fish together can all lead to contamination and sickness.
I for one, love sushi but I will leave it up to the pros, that is unless one of my buddies brings in a bluefin. I once treated a Japanese friend with raw bluefin that was caught only hours before. But my favorites are usually cooked or cured.My favorite is unagi, which is grilled eel. Unagi can only be served cooked because eel blood is toxic to humans. And even after talking about salmon parasites I love salmon nigiri, but I only get smoked salmon.